Three Dots (1)
(John Banks)
The King is about to die. He sends messengers throughout the land seeking for
the 3 smartest people. Finally 3 are found. He gives them a task to see which
one is the wisest.
He tells them, "I will seat you in a triangle so that each of you faces the
other two. After you are blindfolded I will paint a dot on each of your
foreheads. Each dot will be red or green so that there can be any combination of
red and green dots, for example, 1 red and 2 greens, or all red, etc. When I
remove the blindfolds each of you must raise your hand if you see _any_ green
dots, i.e. 1 or 2 dots. As soon as you have figured out what color your own dot
is, tell me how you knew."
So he seats them, blindfolds them, and then paints a green dot on all three
foreheads. When the blindfolds are removed, all three hands go up. After a long
pause, the wisest person says, "Your highness, I have a green dot. The reason I
know this is that..."
How did he know?
Extra credit: assume there are 4 people and all have green dots... can our hero
figure it out now?
Note: please don't write, "He knew because he saw that two other hands were up!"
or "He guessed!," or, "He saw the reflection in their eyes!" or "He recognized
the smell of the paint!" or other such drivel! If any of those kinds of answers
were correct, it would be a terrible riddle!
Three's a Crowd
(Clayton Lewis)
After hearing about the three wise folks three scoundrels claim to be the
smartest in the country. So you decide to give them a challenge. Suspecting that
the thing they care about most is money, you give them $100 and tell them they
are to divide this money observing the following rule: they are to discuss
offers and counter-offers from each other and then take a vote. Majority vote
wins.
Sounds easy enough... now the question is, assuming each person is motivated to
take the largest amount possible, what will the outcome be?
Note: careful... if the answer were that they split it 50% / 50% / 0%, or 1/3 /
1/3 / 1/3, it wouldn't be a riddle!
Lying Defeeted
(John Banks)
You are visiting an island on which two tribes of natives live. One tribe has
purple soles and always lies; the other tribe has green soles and always tells
the truth. There are three natives standing near you. You can't see the bottoms
of their feet, and indeed you find out it is extremely rude to look at another's
soles, but you are curious so you ask the first man,
"Sir, what color are your soles?" Now he happens to understand English, but he
can't speak it, so he replies in his native tongue, "Glub Glub". Though you
don't speak the language, you know that "Glub Glub" either means purple or
green.
You turn to the second man and ask, "Sir, what did he say?" The second man
replies, "He said he has green soles."
Now to be sure, you turn to the third and ask, "Sir, what color of soles does
this second man have?" The third man replies, "Sir, he has purple soles."
Now the question is, what color of soles does the third native have?
Open Door Policy
(John Banks)
You are traveling in a deep dark forest and get lost. A trap door suddenly opens
and you fall down into a dark chamber.
You hear a voice, "You are trespassing and the penalty is death. In five minutes
you will be buried alive. However due to our exceeding kindness and mercy, we
will allow you to earn your life back. In this dark chamber there are two doors.
You may choose to open either one - if you choose correctly, you will go free.
If you choose incorrectly, well, instead of just being buried alive, you will be
eaten alive by army ants.
To help you choose a door, you may ask a question. However, you should know that
two people will hear you and one of them always lies and the other one always
tells the truth. One of them will answer your question, but you will not know
which one. Each of them knows which door leads to freedom.
Good Luck, you have four and a half minutes left."
What question do you ask to win your freedom? (At least two solutions.)
Trouble in River City
(John Banks)
After asking the right question (Open Door Policy), you are allowed to walk
through the Door of Freedom. After taking a few deep breaths of fresh air, you
set out to escape this deep dark forest. As fate would have it, you feel a thud
on your noggin and wake up in a dimly lit room with a pool table. You are about
to be challenged to a game of 9-ball when the wicked forest people notice chalk
on your hand. Wary of the possibility of you turning out to be a pool shark,
they give you this challenge instead.
On the pool table are 12 balls of identical size. And all are of identical
weight except one, which is either slightly heavier or slightly lighter than all
the others, but not enough for you to be able to tell just by holding it.
Now the evil forest people bring a balance scale so that you may compare objects
against each other. "No problem" you're thinking. "I'll just compare them to
each other to find the exception." However, you are then informed that you may
only use the scale three times.
How do you use the balance scales so that in just three comparisons, you find
the one suspicious ball and know whether it is heavier or lighter?
Hints:
If you think you are looking for a heavier ball, please re-read the riddle.
If you have no life and are interested in solving this riddle :-) then click
here for answer format. because if you don't understand the answer format,
you don't understand the riddle!
Asphynxiation
(Eddie Gioia)
After figuring out how to use the scales just three times to find the odd ball,
you are released back into the forest. You are walking along minding your
business when a snare suddenly grabs your foot and yanks you upside down 30 feet
off the ground. When you stop swinging you realize you won't be able to just
climb up the rope, because you are right beneath a large platform with no holds
on the bottom. You examine the rope and see that there is no way to untie it.
"If only I had a knife..." Then you notice slight movement at the underneath
edges of the platform and see that the movement is actually thousands of army
ants beginning to move down over the platform to the underside and towards you.
They look exceedingly hungry. They don't look like vegetarians.
When things look hopeless, you notice a sphynx couple sitting on a huge branch.
One of them throws a knife into the air and when it comes back down, they both
reach for it. You cannot tell which one actually grabbed it. All you know is
that you need that knife to cut yourself down.
The husband says "The sphynx with the knife always tells the truth." But the
wife counters, "He's wrong, the sphynx with the knife always lies." As luck
would have it, one of them always lies and one of them always tells the truth.
Using only these two statements as data, you get one chance to guess who has the
knife.
The ants are approaching, who has the knife?
Hat-Trick
(Bobby Dragon2)
After calmly figuring out who had the knife, you cut the rope just as an army
ant reaches it. You are lucky and fall into a pile of leaves, bounce up and land
in a chair. As you start to look around you hear a stearn voice say, "Eyes
forward!"
There are two people sitting behind you, so there are three people facing the
same direction. The other two are the two smartest people in the forest (a scary
thought). There are five hats: three are red and two are white.
While all of your eyes are closed, a hat is placed on each person's head and the
two unused hats are hidden. Then all are allowed to look only forward so that
each of you can only see the people in front of you (the person in the back can
see the hats of the two people in front; the middle person can see your hat; you
can't see any hats at all; so you might as well keep your eyes closed!)
When someone figures out what color hat they are wearing, they must call out. No
one has called out yet. What color hat are you wearing and how do you know?
Light Bridge
(various - most recently James Spell)
After you figure out that you were wearing a Cowboy hat all along, (Hat-Trick)
you decide to go home. Unfortunately you must take an old, old bridge across a
deep, dark chasm. It is dark and there are so many steps missing that you ask to
borrow a flashlight. Three forest people approach and offer you a flashlight in
return for helping them across the bridge. Now the bridge allows a maximum of 2
people at once and for safety, there must always be someone on the bridge
holding a flashlight (of which there is only 1). In addition, the three forest
people take 2, 5, and 10 minutes respectively to cross the bridge. You, being
highly motivated, need only 1 minute.
No problem, you think, we'll just take turns walking folks back and forth with
the light until we're all across. But the bridge is enchanted and every million
years, it vanishes for a century and that will happen in exactly 17 minutes.
How will all four of you make it to the other side of the bridge in 17 minutes?
(Note: Call these people #1 #2 #5 and #10. If you and #10 go across and you
return, that takes 11 minutes. Then you and #5 could go across and you return;
we are now up to 17 minutes... *poof* - bridge is gone.
The light carrier doesn't have to be you. The light carrier must accompany
another person the whole way across - you cannot have one person stand in the
middle and shine the light. No piggy-backs, etc..)
Auction Action
(Clayton Lewis)
You are attending a party of the forest people when Prof. Chaos arrives. Folks
look bored, so she decides to engage in a little mischief. "I will give this
$100 bill to the highest bidder. The only rule is that the person who bids the
second highest amount will also have to pay me that bid. The highest bidder
takes the bill, even if the highest bid is only 5 cents."
People start to murmur. Then you hear "A nickel!". "A Dime!". "Two Dollars!"...
Question: what is Prof. Chaos up to?
No Vacancy
(Brady Smith)
In the forest, a hotel has an infinite number of rooms. An infinite number of
forest people arrive and each takes a room. So far so good. Now you would like a
room.
Can the hotel accomodate you? If so, how?
(Please enjoy this riddle instead of writing that infinity is the same as
infinity plus 1 or some such gibberish! Folks who send me stupid definitions
("Infinity is, you know, like never ending, so, like, sure, they'd all have
rooms, you know, like duh.") are almost without exception the least
knowledgeable about infinity! So have fun with it; ask yourself what you'd do if
you were the inn-keeper. However, you must find _rooms_ for everybody, no
doubling up, sleeping in the kitchen etc.)
No Vacancies
(Brady Smith)
The hotel has an infinite number of rooms. An infinite number of forest people
arrive and each takes a room. So far so good. Now another infinite number of
guests arrive.
Can the hotel accomodate them all? If so, how?
(see the note above on "No Vacancy")
Timing is Everything
(Riki Maicas)
A man comes home from work by train every day. He gets to the train station at 5
pm and from there his dog picks him up in the car. One day this arrived at the
station at 4 pm and decided to start walking and meet his dog somewhere between
the train station and home. His dog drove the car as usual; met him on the road
before reaching the station, and took him home.
That day, they got home 20 minutes earlier.
Question: How long had the man been walking?
(Tips: not 20 minutes; not 40 minutes; of course dogs can drive)
Use it or Lose it
(Eric at the roof)
And now, for something completely different...
He who makes it does not want it.
He who buys it does not use it.
He who uses it does not know it.
What is it?
Enlightenment
(various)
You're standing before a closed, solid, light-proof door which opens into a
room. Inside the room is a lamp which is now off. Next to the door are three
switches. One of these three switches turns the lamp in the room on and off.
Your job is to figure out which switch controls the lamp. However, you can't
just open the door and look. In fact, you can only enter the room one time and
then you have to say which switch controls the lamp. There are no windows,
holes, cracks, leaks, bleeding-heart-liberals, etc. You are allowed to set any
switches on or off and then enter the room. That's it.
What will you do to know with certainty which switch controls the lamp?
Links
Easy, Medium, and Hard Puzzles - nice assortment.
Chimera's IQ Test Riddles
If you think you will receive answers by writing to the email address below,
then please read the top of this page again.
Contact webmaster@twinbear.com Copyright (©) 1997, 1998 Brent Neal
Reeves Last edited: late 20th Century